EXP1 is required for organisation of EXP2 in the intraerythrocytic malaria parasite vacuole
EXP1 is required for organisation of EXP2 in the intraerythrocytic malaria parasite vacuole
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DOI：
10.1111/cmi.13168
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发表时间：
2020-02-12
影响因子：
3.4
通讯作者：
Beck, Josh R.
中科院分区：
文献类型：
--
作者：
Nessel, Timothy;Beck, John M.;Beck, Josh R.
红细胞内疟疾寄生虫位于紧密覆盖寄生虫质膜的寄生虫空泡膜（PVM）内。虽然PVM是寄生虫生存所必需的几个运输活动的网站，该膜系统的组织的基础是未知的。在这里，我们在PVM上用BioID 2进行了邻近标记，突出了一组单程整合膜蛋白，它们构成了PVM蛋白质组的主要组成部分，但其功能尚不清楚。我们通过调整CRISPR/Cpf 1基因组编辑系统来安装TetR-DOZI-适体系统以进行条件翻译控制，从而研究了该组中已知最长的成员EXP 1。重要的是，虽然EXP 1是所需的红细胞内的发展，以前报道的体外谷胱甘肽S-转移酶活性不能解释这种基本的EXP 1功能在体内。EXP 1敲低伴随着液泡超微结构的深刻变化，包括PVM与寄生虫质膜的分离明显增加和异常膜结构的形成。此外，虽然输出的蛋白质的疟原虫易位子的活性不受EXP 1的耗尽的影响，易位子孔形成蛋白EXP 2的分布，而不是HSP 101解折叠酶的显著改变。总的来说，我们的研究结果揭示了一种新的PVM缺陷，表明EXP 1在维持PVM内EXP 2的正确组织中起着关键作用。
Intraerythrocytic malaria parasites reside within a parasitophorous vacuole membrane (PVM) that closely overlays the parasite plasma membrane. Although the PVM is the site of several transport activities essential to parasite survival, the basis for organisation of this membrane system is unknown. Here, we performed proximity labeling at the PVM with BioID2, which highlighted a group of single-pass integral membrane proteins that constitute a major component of the PVM proteome but whose function remains unclear. We investigated EXP1, the longest known member of this group, by adapting a CRISPR/Cpf1 genome editing system to install the TetR-DOZI-aptamers system for conditional translational control. Importantly, although EXP1 was required for intraerythrocytic development, a previously reported in vitro glutathione S-transferase activity could not account for this essential EXP1 function in vivo. EXP1 knockdown was accompanied by profound changes in vacuole ultrastructure, including apparent increased separation of the PVM from the parasite plasma membrane and formation of abnormal membrane structures. Furthermore, although activity of the Plasmodium translocon of exported proteins was not impacted by depletion of EXP1, the distribution of the translocon pore-forming protein EXP2 but not the HSP101 unfoldase was substantially altered. Collectively, our results reveal a novel PVM defect that indicates a critical role for EXP1 in maintaining proper organisation of EXP2 within the PVM.